package com.xzc.servlet;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class ContextServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1、获取 web.xml 中配置的上下文参数 context-param
        ServletContext context = this.getServletConfig().getServletContext();
        String username = context.getInitParameter("username");
        System.out.println("context-param参数的值是：" + username);
        //2、获取当前的工程路径，格式:/工程路径
        System.out.println("当前工程路径：" + context.getContextPath());
        //3、获取工程部署后在服务器硬盘上的绝对路径
        System.out.println("工程部署的路径是：" + context.getRealPath("/"));
        //4、像 Map 一样存取数据
    }
}
